Study Questions Exam 4
Study Notes Exam 4
1. Plasma: fluid component of blood; Interstitial fluid (IF): fluid in spaces between tissue cells - includes lymph, CSF, synovial fluid, serous fluid, etc...
2. electrolytes: molecules that do dissociate in water into charged particles (e.g.: inorganic salts, organic & inorganic acids & bases, some proteins); nonelectrolytes: molecules that have no electrical charge; do not dissociate in water (e.g.: organic molecules such as glucose, lipids, creatinine & urea)
3. extracellular fluid: chief ions are sodium cations (positive ions) & chloride anions (negative ions); intracellular fluid: chief ions are potassium cations & phosphate anions
4. water intake: 60% fluids, 30% water in foods, 10% from metabolism; water output: 60% excreted in urine (sensible water loss), 28% vaporizes out of lungs of is lost by diffusion through skin (insensible water loss), 8% lost through perspiration & 4% in fecal waste
5. thirst center: hypothalamus
6. dehydration: water moves from cells to ECF to equalize osmolality; hypotonic hydration (water intoxication): water flows into cells by osmosis; edema: fluid movement from blood to interstitial space
7. 85-90% sodium is reabsorbed in the proximal tubules & loop of Henle without aldosterone; when aldosterone levels are high, nearly all the remaining sodium is actively reabsorbed from the distal tubules & collecting ducts; renin released by JG cells converts angiotensinogen to angiotensin I, & angiotensin I is converted to angiotensin II by angiotensin converting enzyme (ACE) – angiotensin II activates release of aldosterone from adrenal cortex
8. baroreceptors are pressure receptors in the heart & large vessels (aorta & carotid arteries); activation of baroreceptors results in constriction of afferent arterioles, decreased glomerular filtration rate & decreased sodium & water output -> increased blood pressure
9. ADH is produced in the hypothalamus & stored & released from the posterior pituitary; ADH increases water reabsorption from the collecting ducts
10. aldosterone increases blood pressure; ADH increases blood pressure; atrial natriuretic peptide (ANP) decreases blood pressure
11. potassium ions are important for electrical conduction in neurons & muscle cells; in the presence of aldosterone, for each sodium reabsorbed, a potassium ion is secreted to maintain electrolyte balance
12. parathyroid hormone increases blood calcium levels; calcitonin decreases blood calcium levels
13. blood pH is normally maintained between pH 7.35-7.45
14. acidosis: blood pH < 7.35; alkalosis: blood pH > 7.45
15. bicarbonate buffer system: mixture of carbonic acid & its salt sodium bicarbonate in the same solution; stabilizes blood pH; phosphates & proteins can also act as buffers in blood
16. carbon dioxide from metabolism enters blood & combines with water to form carbonic acid -> lowers pH
17. during acidosis: bicarbonate ions generated while excreting hydrogen ions; during alkalosis: bicarbonate ion secretion while reabsorbing hydrogen ions
18. male gamete is sperm produced in testes; female gamete is ovum (egg cell) produced in ovaries
19. temperature of testes is maintained by contraction & relaxation of dartos & cremaster muscles
20. sperm are produced within seminiferous tubules of testes
21. interstitial cells (Leydig cells): located in areas surrounding seminiferous tubules; produce androgens (testosterone)
22. erectile tissue in penis: corpus spongiosum & corpora cavernosa; become filled with blood during sexual excitement
23. seminiferous tubule -> straight tubule -> rete testis -> efferent duct -> epididymis -> ductus deferens -> ejaculatory duct -> (prostatic) urethra
24. seminal vesicles: secrete seminal fluid – contains nutrient for sperm (fructose), prostaglandins that aid in sperm motility & its alkaline nature helps to neutralize penile urethra; prostate gland: secretes a slightly acidic fluid containing citrate (can also be used in energy pathways by sperm), enzymes & prostate-specific antigen (PSA) to break down clotting proteins in semen; bulbourethral glands (Cowper¹s glands): produce thick clear mucus prior to ejaculation that neutralizes acidic urine in urethra
25. fructose for ATP production by sperm; prostaglandins aid in sperm motility & may stimulate uterine contractions to propel sperm through female tract; seminalplasmin is an antibiotic (destroys bacteria)
26. meiosis in males is spermatogenesis; meiosis in females is oogenesis
27. normal diploid chromosome number (2n) in humans is 46; normal haploid chromosome number (n) in humans is 23
28. meiosis I: reduction division (2n to n)
29. synapsis: homologous chromosomes pair & exchange genetic information; tetrads or bivalents: chromosomes in the act of ³crossing over²; independent assortment: either maternal or paternal chromosome of each homologous pair can be on a given side of metaphase plate; each occurs during meiosis I
30. spermatogonium: 2n stem cell -> divides to form primary spermatocyte (2n) -> divides in meiosis I to form secondary spermatocytes (n) -> divide in meiosis II to form spermatids (n) -> differentiate to form sperm cells
31. spermiogenesis: spermatids undergo changes to form sperm cells; flagellum is for locomotion; acrosome contains hydrolytic enzymes for penetration of egg cell
32. sustentacular cells (Sertoli cells) surround cells of seminiferous tubules & connect to one another by tight junctions which form blood-testis barrier that prevents immune cell targeting of sperm
33. Gonadotropin-releasing hormone (GnRH) release from hypothalamus controls release of follicle-stimulating hormone (FSH) & luteinizing hormone (LH) from anterior pituitary; FSH stimulates sustentacular cells to release androgen-binding protein (ABP), which causes spermatogenic cells to bind testosterone & begin spermatogenesis; LH binds to interstitial cells & stimulates them to secrete testosterone; testosterone feeds back (negative feedback) to hypothalamus & anterior pituitary, inhibiting release of GnRH & tropic hormones; inhibin released by sustentacular cells inhibits release of FSH from anterior pituitary & GnRH from hypothalamus
34. ovaries: female gonads; produce oocytes & female sex hormones (estrogens & progesterone)
35. ovarian follicles: in cortex; contain immature egg (oocyte) encased by one or more cell layers (1 layer = follicle cells; more than 1 layer = granulosa cells); primordial follicle: one layer of squamous cells enclose oocyte; primary follicle: 2 or more layers of cuboidal or columnar cells surround oocyte; secondary follicle: has central fluid-filled cavity (antrum); vesicular (Graafian) follicle: follicle bulges from ovary surface; oocyte sits on stalk of granulosa cells at one side of antrum
36. uterine tube: infundibulum, ampulla & isthmus; fertilization normally occurs within uterine tube (generally ampulla, although sometimes fertilization occurs within infundibulum or even pelvic cavity); fimbriae located at end of infundibulum, & have cilia that sweep oocyte into uterine tube
37. uterus: consists of fundus, body & cervix; cervical canal communicates with vagina
38. perimetrium: serous membrane, myometrium: smooth muscle, endometrium: mucosa with simple columnar epithelium; stratum basalis (basal layer): forms new functional layer after menstruation, stratum functionalis (functional layer): undergoes cyclic changes in response to ovarian hormones; functional layer shed during menstruation
39. ovarian ligament anchors ovary to uterus; round ligament: anchors uterus to anterior abdominal wall
40. wall of vagina consists of outer fibroelastic adventitia, smooth muscle muscularis & mucosa of stratified squamous epithelium with ridges (rugae); pH of vagina is normally acidic due to metabolism of sugars by resident bacteria
41. clitoris contains erectile tissue (corpora cavernosa)
42. mammary glands are composed of modified sweat glands; lobules within lobes contain alveoli that produce milk
43. oogonium: stem cell in ovary that differentiate into a primary oocyte; primary oocyte: cell formed from oogonium that is committed to producing gamete (egg); secondary oocyte: cell resulting from meiosis I in the ovary; ovum (egg cell): functional gamete resulting from meiosis II in ovary; polar body: nonfunctional cell produced by meiosis I & meiosis II in ovary
44. primary oocytes arrest in prophase of meiosis I, each month after puberty, several primary oocytes complete meiosis II in response to FSH & LH from anterior pituitary; secondary oocytes arrest in metaphase of meiosis II, sperm penetration of secondary oocyte is the signal to complete meiosis II
45. spermatogenesis: 4 gametes (sperm cells); oogenesis: 1 gamete (ovum) & 2 or 3 polar bodies
46. follicular phase: primordial follicle®primary follicle®secondary follicle®vesicular (Graafian) follicle (days 1-14); ovulation: bulging ovary wall ruptures & releases secondary oocyte into peritoneal cavity; (~ day 14); luteal phase: period of corpus luteum activity, corpus luteum secretes progesterone & estrogen for ~ 10 days & degenerates if fertilization does not occur (days 14-28)
47. GnRH released from hypothalamus stimulates FSH & LH release from anterior pituitary; FSH & LH released from anterior pituitary & stimulate follicle growth & estrogen secretion; estrogen secreted by follicle cells & corpus luteum (& placenta), feeds back to anterior pituitary inhibiting release (while stimulating production) of FSH & LH, prepares embryo for implantation & peak levels stimulate burst of LH from anterior pituitary that signals ovulation; progesterone released by corpus luteum (& placenta) works with estrogens to prepare endometrium for embryo implantation, prepares mammary glands for milk production, inhibits GnRH & LH release
48. menstrual phase (days 1-5): uterus sheds all but deepest layer of endometrium, passes out through vagina as menstrual flow; proliferative phase (days 6-14): rising estrogen levels stimulate endometrium to rebuild itself, ovulation at ~ day 14; secretory phase (days 15-28): increasing progesterone levels prepare endometrium for embryo implantation
49. gonorrhea: caused by bacterium Neisseria gonorrheae; syphilis: caused by bacterium Treponema pallidum; chlamydia: caused by parasitic bacterium Chlamydia trachomatis; genital warts: caused by human papillomavirus (HPV) (certain types also cause invasive cervical cancer); genital Herpes: caused by human herpesviruses (herpes simplex virus, Epstein-Barr virus)
50. conceptus: developing offspring; gestation period: time of development; from last menstrual period until birth; preembryo: first 2 weeks of development; embryo: third through eighth weeks (embryonic period); fetus: ninth week through birth (fetal period); zygote: fertilized ovum
51. sperm viable from 24 hours up to 72 hours; egg viable for 12-24 hours after ovulation
52. acrosomal reaction: release of acrosomal enzymes from sperm that break down protective covering of oocyte; corona radiata & zona pellucida of oocyte must be broken down for sperm to gain entry into oocyte
53. fast block to polyspermy: membrane depolarizes due to sodium ion entry through open sodium channels; cortical reaction: cortical granules within oocyte release enzymes that destroy sperm receptors
54. sperm nucleus enters oocyte (tail & midpiece are lost); oocyte completes meiosis II to form the ovum nucleus (and second polar body, which is ejected); ovum & sperm nuclei become female & male pronuclei their nuclear membranes rupture & release their chromosomes, which combine to form the zygote
55. cleavage: in embryonic development, a period of rapid mitotic divisions of the zygote following fertilization, resulting in doubled numbers of increasing smaller cells called blastomeres; blastomeres: cells resulting from cleavage (up until blastocyst stage); morula: berry-shaped cluster of 16 or more cells; blastocyst: fluid-filled hollow sphere of cells composed of trophoblast, blastocele, & inner cell mass; gastrula: embryonic structure consisting of embryonic disc with 3 primary germ layers (endoderm, mesoderm & ectoderm)
56. trophoblast cells secrete hCG & enzymes to help in implantation, & give rise to the chorion, which begins formation of placenta; inner cell mass becomes the embryonic disc, which forms the embryo
57. implantation: attachment of embryo to endometrium of uterus, ~ 6 days after fertilization
58. placenta arises from trophoblast of embryo & endometrial tissue of mother
59. amnion: sac containing amniotic fluid (from maternal blood & fetal urine) that cushions & protects embryo against trauma & maintains temperature; yolk sac: produces earliest blood cells & vessels and is the source of primordial germ cells that form gonads; allantois: the structural base for umbilical cord formation & forms part of urinary bladder
60. ectoderm, mesoderm & endoderm; ectoderm: forms nervous system (brain, spinal cord, cranial & spinal nerves), epidermis of skin (also forms: accessory structures of skin (hair follicles, nails, glandular epithelium), outer & inner ear, lens, cornea, & epithelium of several glands); mesoderm: forms all connective tissues, dermis of skin, skeletal, cardiac & most smooth muscle, blood, bone marrow & lymphatic tissue (also forms: endothelium of vessels, sclera & choroid of eye, middle ear, mesothelium & epithelium of several organs); endoderm: forms: epithelium of respiratory & GI tracts, epithelium of bladder, gallbladder & liver & epithelium of several glands
61. neurulation: differentiation of ectoderm (in response to signals from notochord) to form neural tube, which develops into brain & spinal cord
62. somites: formed from mesoderm; sclerotome: produces vertebra & rib; dermatome: helps form dermis of skin; myotome: forms skeletal muscles
63. intermediate mesoderm: forms gonads & kidneys; somatic mesoderm: helps form dermis, parietal serosa & bones, ligaments & dermis of limbs; splanchnic mesoderm: forms heart, blood vessels & most connective tissue
64. ductus venosus: liver bypass; foramen ovale: pulmonary circuit bypass from right atrium to left atrium; ductus arteriosus: pulmonary circuit bypass from pulmonary trunk to aorta
65. Fetal Ultrasonography: sound waves passed over the abdomen & reflected by the fetus are converted to an on-screen sonogram image; Amniocentesis: amniotic fluid is withdrawn with a hypodermic needle inserted through the mother¹s abdominal wall & into the amniotic cavity within the uterus; Chorionic Villi Sampling: a catheter is guided through the vagina & uterine cervix to chorionic villi, & tissue is suctioned out for chromosomal analysis; maternal alpha-fetoprotein (AFP) test: serum levels of AFP in maternal circulation tested to check for potential fetal nervous system defects
66. corpus luteum secretes progesterone & estrogens during first 3-4 months; placenta secretes progesterone & estrogens from third month through end of pregnancy
67. human chorionic gonadotropin (hCG) from chorion stimulates hormone release from corpus luteum & prevents menstruation
68. oxytocin: causes placenta to release prostaglandins, both are uterine muscle stimulants that initiate contractions; oxytocin also causes milk ejection from mammary gland ducts; prolactin stimulates milk production from mammary glands
69. crowning: when largest dimension of baby¹s head distends vulva; vertex (head-first) presentation: skull of baby dilates cervix; breech (buttock-first) presentation: fetal buttocks or lower limbs enter birth canal first; Caesarian (C) section: delivery of infant through abdominal & uterine walls
70. prolactin-releasing hormone (PRH) from hypothalamus stimulates anterior pituitary to release prolactin
71. alleles: alternative forms of a gene that code for the same trait at the same location on homologous chromosomes; genotype: genetic makeup for a trait or traits; phenotype: physical or outward expression of a gene (appearance for a trait); homozygous: an individual with the same alleles on homologous chromosomes; heterozygous: an individual with different alleles on homologous chromosomes; carrier: heterozygous individuals that carry a recessive gene but do not express it, and can pass the gene on to their offspring
72. incomplete dominance: neither member of an allelic pair is dominant over the other, & the heterozygote has an intermediate phenotype between dominant & recessive phenotypes (example: sickle-cell disease (SCD)); multiple-allele inheritance: inherited traits with more than 2 alleles (example: ABO blood groups); codominance: more than 2 alleles fully expressed (example: ABO blood groups)